What motor are you running?
I've got a 2F, SM420, spring over, 4.11's and 36x14.50's. If you're motor is strong, the 4.11's will work fine on the road. I can cruise at 75 easily on the highway. If I could afford it though, I'd probably go with 4.88's as I don't drive it that much and I trailer it to the trail.

The SM420 will actually make it worse on the road. First doesn't get used, so you use 2,3, and 4. The gap between 2nd and 3rd is huge, so you need good power to go through it. 4th is 1:1 just like what you have now so no difference there.

SM420 won't do squat for ya in town, actually will make things worse, as noted.

IMO, install the tires and see what you think...it's easy to make that a two-step process and decide later. Since no two people have the same expectations for street driving, it may drive ya nuts, or you may not care.

I run 38.5's on my stock 4.11 gears, but have the added power of the 350 TBI. No complaints, but my rig has the granny and is 95% trail use only anyways. For a couple hundred miles of road time, most of that between trails, I wasn't investing in gears...